A newly declassified report is shedding light on anti-Israel material found in U.S.-funded textbooks used by the United Nations' Palestinian refugee agency (UNRWA) in Palestinian schools -- while faulting the State Department for leaving out key information in updates to Congress.

The report on the textbook content of UNRWA schools was completed in April last year but was then classified. Republican lawmakers have been calling for its declassification ever since, and last week succeeded in that push.

The report found that some textbooks in UNRWA-run schools did not mention Israel or Judaism and included regional maps that excluded Israel while referring to Israeli cities as Palestinian. They included math problems that challenged pupils to identify the number of Palestinian casualties in the First and Second Intifadas. The report will fuel long-standing concerns from conservatives that the U.S. was funding anti-Semitism and anti-Israel sentiments via funding for UNRWA, which was halted last year.

Between 2015 and 2017, the U.S. provided $243 million in educational aid to the West Bank and Gaza via the State Department and USAID. But the Government Accountability Office (GAO) report found that Congress was unable to properly assess the material in the textbooks because of the State Department’s misleading updates to the body in three annual reports during that time frame.

"Although State submitted its required reports to Congress on time, State included inaccurate information in the 2017 report and omitted potentially useful in all three reports," the GAO report says.

Two of those annual reports were published during the Obama administration, while the last one was published in the first months of the Trump administration. Since then, the Trump administration has taken a much tougher stance toward UNRWA, and last year cut all funding to the body as well as to the Palestinian Authority. It forms part of a broader push by the administration against alleged anti-Israel bias at the U.N.

In particular, the GAO faults State for reporting that UNRWA had completed training teachers and distributed "complementary teaching materials" to address the problematic content that had been identified, when it had not. The department also omitted information about whether UNRWA found that any materials included content that was classified as "incitement" or that did not promote human dignity.

"Our analysis also showed that State's required reports did not include some information that could be useful for congressional oversight of whether UNRWA is taking steps to ensure that all the content of all educations materials currently taught in UNRWA schools and summer camps is consistent with the values of human rights, dignity, and tolerance, and does not include incitement," the report says.

Rep. Scott Perry, R-Pa., and Lee Zeldin, R-N.Y., who pushed for the report to be declassified, said that American taxpayers had unknowingly funded “systematic hatred.”

“The failures of the State Department and UNRWA allowed systematic anti-Semitic and anti-Israel ideas to flourish in UNRWA schools in the West Bank and Gaza,” Perry said in a statement. “The harsh reality is that the American taxpayers were unknowingly funding this systematic hatred because key information was withheld from the American public – including my constituents.”

Sen. Ted Cruz, R-Texas, in a statement to Fox News, described the report’s conclusions as “completely unacceptable.”

“UNRWA promotes anti-Semitic incitement, and institutionally they have often and regularly lashed out against the United States despite receiving funding from the U.S. government," he said. "This report troublingly suggests that Congress may not have been getting the information it needed to exercise proper oversight, including from parts of the U.S. government. If that turns out to be true, it's completely unacceptable."

In a statement to Fox News, the State Department noted that the GAO report concluded that State took steps to address problematic content. It said it agreed with the GAO recommendations and has taken steps to implement them immediately.

It also disputed the claim that it had misled Congress, saying that its 2017 report -- which claimed UNRWA distributed complementary teaching materials -- was, in fact, accurate based on the information the department had at the time.

A State Department spokesman also said the department is “committed to monitoring and combating incitement to violence in Palestinian textbooks” and it has engaged with the Palestinian Authority directly to flag “problematic content.”

David Bedein, who as director of the Center for Near East Policy Research has studied the UNRWA curriculum for years, told Fox News that, “State [misreported] to Congress that it had developed alternative materials to the anti-semitic and pro- incitement PA school curriculum.”

“In the GAO report, State cannot explain why that such existing alternative materials were never implemented and have never been seen in the UNRWA classroom,” he said.

Bedein praised the work of Sen. James Risch, R-Idaho, the new chairman of the Senate Foreign Relations committee, who also pushed for the report's release: “Thanks to the integrity of Senator James Risch, the issue of UNRWA 'education' will now see the light of day. He stood by his principles because of issues of fundamental integrity. “

In its response to the report, UNRWA told the GAO that its program strives to "realize the potential of all its Palestinian refugee students, to help them develop into confident, innovative, questioning, thoughtful, tolerant and open-minded critical thinkers, who uphold human values and tolerances, and contribute positively to the development of their society and the global community."

In its statement to Fox News, the State Department noted the decision to cut funding to UNRWA, and described the refugee agency as operating in "permanent crisis mode."

“UNRWA’s business model, which is tied to an endlessly and exponentially expanding community of beneficiaries, is unsustainable and operates in permanent crisis mode,” the spokesman said. “As we announced in August 2018, the United States will no longer commit to funding UNRWA.”

Adam Shaw is a reporter covering U.S. and European politics for Fox News.. He can be reached here.